2005 MAG 350 MPI - Oil Pressure Switch Change

[stelios hondrcolos]

I am trouble shooting no power to the fuel pump and now looking at the oil pressure switch.
Have already changed fuses, relays. I have power to the relay.
Reading the forums, Ive seen people say the oil pressure switch (not gauge sender) is located behind the distributor on the back of the engine, but the attached manual diagram (position 'C' ) says its low on the left side of the engine, near the pressure sender. I don't even know if access is good enough where I can get to it to change it. I cant get an available mechanic to the boat for weeks. Has anyone done this that can lend some practical help? After this will look at harness wiring. Thanks.

 

[dlvwill]

My 2004 MAG 350 MPI is at position C, right above where the oil filter would generally mount. Unplug and jump the wires to see if you get power to the fuel pump.

 

[Espos4]

Do you have continuity on the wire from the relay down to the fuel pump module?

Do you have power and ground at the relay when you turn the ignition on?

What happens when you disconnect the relay and use a jumper wire across the terminals to connect your 12v to the power wire heading down to the fuel op module? Does the pump turn on then?

 

[stelios hondrcolos]

Ok I located the switch but I can’t access it without removing the port engine riser, etc. to get down there.
Is that how people do it? Or use the Braille method with skinny arms ?

 

[Fun Times]

Ok I located the switch but I can’t access it without removing the port engine riser, etc. to get down there.
Is that how people do it? Or use the Braille method with skinny arms ?

That appears to be the knock sensor merc part number 8M6003194,

Also on MPI engines, there really isn't an oil switch per se th
at controls the fuel pump power, generally speaking that only happens on the carbureted engines..., Genuine Mercury & Mercruiser parts. Electrical Components

Espos4 suggestions are worth focusing on or maybe the ECM needs internal checking inspections done, Mercury PCM Repair (whipplesuperchargers.com)

 

[stelios hondrcolos]

That appears to be the knock sensor merc part number 8M6003194,

Also on MPI engines, there really isn't an oil switch per se th
at controls the fuel pump power, generally speaking that only happens on the carbureted engines..., Genuine Mercury & Mercruiser parts. Electrical Components

Espos4 suggestions are worth focusing on or maybe the ECM needs internal checking inspections done, Mercury PCM Repair (whipplesuperchargers.com)

 

[stelios hondrcolos]

Sorry that was the wrong photo.
See diagram Part C